Making a perfectly square (or round) undistorted image in modern Drupal 8 9 10

Relative crop in does the necessary step.

All the effects available with this module:

To quote my own commit message:

Add Image Effects module just for ‘Relative Crop’

(same effect used to be possible with an inner/outer checkbox for regular crop, but no more, Drupal, even though it still lies and says it can make perfect squares).

Unrelated but kind of cool? Make images about the same relative size while allowing dimensions to vary: